The most common causes of vaginal discharge are:
• thrush (vaginal candidiasis) - a non-sexually transmitted fungal infection (usually with a fungus called Candida) that commonly affects the vagina: discharge is typically discharge is thin and watery or thick and white (like cottage cheese), but lacks a strong smell; associated with intense itchiness.
• bacterial vaginosis - a bacterial infection of the vagina, characterized by vaginal discharge that is gray and/or produces a strong fishy smell, particularly after sexual intercourse. It is the result of an imbalance in the normal bacteria found in the vagina. It does not usually cause itching or irritation. Like vaginal candidiasis, bacterial vaginosis is a rather common condition and is not sexually transmitted. Treatment is with antibiotics.
• trichomoniasis - a common sexually transmitted infection (STI) caused by a parasite. Vaginal discharge becomes frothy (bubbly and has blood in it), yellow or green, it may also be copious and may also have a fishy smell. Other possible associated symptoms include soreness, swelling and itching around the vagina, and pain when passing urine. Trichomoniasis is easily treated with an antibiotic
• gonorrhoea or chlamydia - STIs caused by two bacteria, Neisseria gonorrhea and chalmydia trachomatis, respectively. We suspect these infections if vaginal discharge is abnormal and the patient complains of pain in the pelvis or upon urination, or there is bleeding between periods or after sexual intercourse. Gonorrhoea can make vaginal discharge turn green, although often the pain or bleeding are more prominent. These infections require prompt treatment with antibiotics in both the patient and all possible sexual partners.